Glass substrates are currently being used as protective covers or windows for display and touch sensor devices, as well as substrates for front and back planes of electronic devices. As such, these substrates are susceptible to mechanical failure originating at flaws at the edges of the substrate. Such flaws are either created during the cutting and edge finishing process or from contact damage occurring during handling and use.
Edge finishing, which includes grinding, polishing, and/or etching of the edges of the substrate, attempts to eliminate major flaws that are generated during the cutting process and minimize chipping due to contact damage. In addition, such finishing processes have been focused on preventing damage due to edge impact from point sources. Finishing processes are generally capable of removing flaws generated during scribe and breaking processes and produce edge shapes that are more tolerant of edge impact. However, these finishing processes produce lower edge strength than is achievable. In addition, it is difficult to use such finishing processes when the substrate thickness is below about 0.3 mm. Due to the reduced contact area, substrates having thicknesses in this range are susceptible to breakage during edge impact, whether or not they have been edge finished.